3&#39;, 4&#39;-dichloropropionanilide



United States Patent 3,382,280 3,4-DICHLOROPROPIONANILIDE Clarence W.Huffman, Glenview, Ill., assignor to Monsanto Company, St. Louis, Mo., acorporation of Delaware N0 Drawing. Application May 8, 1961, Ser. No.108,317,

which is a continuation-in-part of abandoned application Ser. No.661,575, May 27, 1957. Divided and this application Feb. 3, 1967, Ser.No. 613,738

1 Claim. (Cl. 260-562) ABSTRACT OF THE DISCLOSURE3,4'-dichloropropionanilide is a new compound which has outstandingherbicidal properties.

Cross-references to related applications This application is a divisionof my application Ser. No. 108,317, filed May 8, 1961, which in turn isa continuation-in-part of my application Ser. No. 661,575, filed May 27,1957, now abandoned.

Background of the invention Weeds may be broadly defined as undesirableplant growth. In certain places, for example, along railroad tracks, anyvegetation thereon is considered a weed and complete eradication of allplants is desired. Of even greater importance is the selective controlof weeds in agriculture, i.e., prevention of growth or extermination ofWeeds without injury to the crops. For example, grass or other plantsgrowing within a corn field are regarded as weeds and they are difiicultto remove, since corn is a member of the narrow-leaf family of plants,as are the grasses. Since the physiological structures of the members ofthe narrow-leaf family are very close, the problem of finding a chemicalwhich has the desired specificity becomes increasingly difficult.Moreover, the selectivity of the chemical must be considered, not onlywith respect to the soil to which it is applied, but also to the effectof the chemical on adjacent crops which are sensitive to this chemical.

Summary of the invention This invention relates to a new compound,3',4-dichloropropionanilide, of the formula:

which has unusual and valuable herbicidal activity. This compound canalso be named 3,4-dichloropropionanilide orN(3,4-dichlorophenyl)propionamide. For convenience, this compound willbe sometimes hereinafter referred to as 3,4-DCPA.

Detailed description The 3,4-DCPA is, of course, applied in an amountsufficient to exert the desired herbicidal cation. The amount of activecompound present in the compositions as actually applied for destroyingor preventing weeds, i.e., unwanted plants, will vary with the manner ofapplication, the particular weeds for which the control is sought, thepurpose for which the application is being made, and like variables. Ingeneral, the herbicidal compositions as applied will contain from about1% to about 75% by weight of 3,4-DCPA, but can contain 90% by weight ormore of 3,4-DCPA.

Valuable herbicidal effects will be observed by applications of smallamounts, for example as low as one-half pound of 3,4-DCPA per acre, aswell as high concentrations, for example pounds per acre. As a generalrule, the selective activity on grasses is exhibited at lower rates ofapplication, from about 0.5 to about 10 pounds per acre. For generalapplication and herbicidal effect on both grasses and dicotyledonousplants, it usually will be found necessary to use amounts in the rangeof 10 to 50 pounds per acre. Herbicidal compositions are prepared byadmixing the 3,4-DCPA in herbicidally effective amounts, with aconditioning agent of the kind used and referred to in the art as a pestcontrol adjuvant or modifier to provide formulations adapted for readyand efficient application to soil or weeds (i.e., unwanted plants) usingconventional applicator equipment.

The herbicidal compositions are applied either as a spray or a dust tothe locus or area to be protected from undesirable plant growth,commonly called weeds, i.e., plants growing where they are not wanted.Such application can be made directly upon the locus or area during theperiod of infestation in order to destroy existing un desirable plantgrowth, and/ or application can be made to the locus in advance of ananticipated weed infestation to prevent such. Thus, the composition canbe applied as foliar sprays and also as sprays directly to the surfaceof the soil. Alternatively, the dry powdered compositions can be dusteddirectly on the plants or dispersed in the surface soil.

Fertilizer materials, other herbicidal and other pest control agents,such as fungicides and insecticides, can be included in the herbicidalcompositions if desired.

The following example illustrates a method of preparing 3,4-DCPA:

EXAMPLE A To a benzene solution containing 161 parts by weight of3,4'-dichloroaniline and 116 parts by weight of triethylamine, there isadded dropwise, through a condenser, 92 parts by weight of propionylchloride. The reaction mixture is agitated and cooling is employed whennecessary to moderate the reaction. The mixture is refluxed until theacyl chloride odor disappears or becomes very faint. Water is then addedto dissolve the precipitated triethylamine hydrochloride and the productis collected by filtration. On recrystallization from cyclohexane, thereis obtained 172 parts by weight of 3',4'-dichloropropionanilide, MP.90.691.6.

Analysis.Calculated for C H C1 NO: C, 49.6; H, 4.13; Cl, 32.5; N, 6.42.Found: C, 49.6; H, 3.90; Cl, 32.4; N, 6.34.

The present invention is illustrated, but not limited, by the followingexamples:

Example 1.Post emergence or foliage tests Seeds of corn, cotton,ryegrass, beans, morning-glory, and pigweed are planted in soil in boxeshaving an exposed area of two square feet. After 23 days, the crops aresprayed with an aqueous emulsion of 3,4-DCPA at a rate of 8 pounds peracre. The emulsion is prepared by dissolving 350 mg. of 3,4-DCPA in 4ml. of methyl isobutyl ketone, adding 12 drops of Agrirnul C (anemulsifying agent sold by Napco Chemical Company which comprises amixture of a polyoxyethylene glycol ester and an alkylaryl sulfonate),and diluting to 40 ml. with distilled water. Application of 10.0 ml. ofthis emulsion per square foot of soil is equivalent to 8.4 pounds ofactive ingredient per acre; however, since some drift loss is inevitablewhen spraying small areas, this rate is assumed to be 8 pounds per acre.Neither the solvent, methyl isobutyl ketone, nor the emulsifying agent,Agrimul C, or a mixture of the two, is toxic to the crops tested.

3 4 At the time of spraying, the crops are in approximately possesslittle or no herbicidal activity. Some of the comthe following stages ofgrowth: pounds are set forth below:

3'-chloroisobutyranilide Corn-1042 inches tall 3'-chloroacetanilideCotton24 inches tall, 3-leaf stage (including primary 54'-b1OmQ-2'-phenylacetanilide leaves) 2',4-dichloropropionanilideRyegrass3-4 inches tall 2,4'-dichloroisobutyranilide Bindweed2-4 inchestall, 35 leaves 2,4',5-trichloroisobutyranilide Bean-6-10 inches tall,primary leaves mature, second tri- 3',4' di h1 i1id foliate leaf about 1inch in diameter 10 2',4'.di th 1 io ilid Pigweed--3-6 inches tall, inbloom due to photoperiod N-methylacetanilide effect.N-n-butylacetanilide p-chloroacetylacetanilide Throughout the course ofthe tests, the boxes are 2,4"dlmeehxlmoplonamhd? watered whenevernecessary. Good growth conditions are z'chloro'z ,4'dlmethylproplonamhde maintained during the test period (60-75 at night,with In the following examples, tables of herbicidal evaluadaytimetemperatures in 7590 range), and the tests are tion data are presentedin which the plants are represented terminated 21 days after spraying.by letters as follows:

Species Fatua. Tectorum. Crusgalli. Perenne. Sanguinalis.

Raphanus-. Sativus. Chenopodiaeae.... Beta Vulgaris. Malvaceae GossypiumNerbaeeum. Amaranthaceae-.. Amaranthus Retroflcxus. Graminae Zea Maize.

Polygenaceae-.-.. Polygonum. Convolvulus. Convolvulaceae.-. Ipomoea..-.Hederacea.

Graminae Setarla Faberii.

.. Arvensis Max. Esculentum. Q. Vulgare. R Satlva. S Usitatisslrnum. TMedieago. Sutiva. U Horsenettle Solanacae Solarium Carolinense. V.Climbing Milkweed. Asclepiadaceae.... Ampelemus Albidus. W. SpurgeEuphorbiaceae..-. Euphorbia Sopma. X. Carpetweed.-. Alzoaceae MollugoVerticillata. Y. Lambsquarter- Chenp0diacue-.. Chenopodium.-.. Album. Z-Smartweed..- Polygonaeeae.--.- Polygonum Pennsylvanicum. (a)..- Cheatgrass..- Graminae Bromus... Sccalinus. (b) Oa s Avena- Sativa (c) WheatTriticum (d)-- Cueumber.... Cucumi (e) Snap beau Phascolus When thetests are terminated, the control crops are Example 2.Post emergencegreenhouse test m approxlmately the followmg stages of growth 3,4-DCPAis retested at various rates by spraying green- Corn-24-36inches tallhouse flats (aluminum pans 9 /2" 1: 5% X 2%") con- Cotton-8-10incl1estall, 7 leaves taining the various plants listed in Table II below withRyegrass--610inches tall aqueous compositions containing varyingconcentrations Bindweed-6 inches tall of 3,4-DCPA. At the time ofspraying the plants are 21 Beans-12-18 inches tall, active blooming,many small days old.

pods developed Throughout the course of the tests, the flats are wateredPigweed12-16inches tall, nearly mature whenever necessary. Good growthconditions are maintained during the test period. The tests areterminated 14 days after the chemical is applied and the results areobserved and recorded.

The relative value of 3,4-DCPA with respect to its herbicidal effect onbroadleaf and narrow leaf plants is indicated by number as follows:

The results of such tests are given in Table 1, below. Percent stand S)is a measure of the number of growing plants in the crops sprayed with3,4-DCPA as compared to the number of growing plants in the untreatedcontrol crops. Percent yield Y) is a measure of the weight of plantgrowth produced with the spray treatment as compared to the weight ofcrops produced without the 0No phytotoxicity spray treatment. lSlightphytotoxicity TABLE I Corn Cotton Ryegrass Bindwced Beans Pigweed Pcr-Per- Per- Per- Per- Per- Per- Per- Per- Per- Per- Percent S cent Y centS cent Y cent S cent Y cent S cent Y cent S cent Y cent S cent Y 34-dichloropropionanilide 0 0 0 0 10 5 0 0 0 0 0 0 The herbicidalefliciency of 3,4-DCPA is surprising, for related compounds posseslittle or no herbicidal efficiency. 2--Moderate phytotoxicity Whentested as described above, aqueous emulsions of a 3Severe phytotoxicityrandom group of such related compounds are found to 4Dead TABLE IL-PosTEMERGENCE RATING Rate,1bs. A B o D E F G H I J K L M N P Q R per acre 74 4 4 4 4 4 4 4 a 4 4 4 4 4 4 4 0 a 1 4 4 4 4 4 4 4 4 4 4 2 0 2 0 4 4 40 4 4 3 4 4 a 0 Example 3.Post emergence field tests Example4.Pre-emergence tests Field test data is obtained on 3,4-DCPA byspraying l3 crops and 11 weed plants at two growth stages (two and fourweeks old). The rates of application employed are 2 lbs. per acre and 8lbs. per acre. This obtained by spraying 30 gallons of the aqueoussolution per acre and varying the concentration of the 3,4-DCPA. Thefollowing water dispersible powder formulation is utilized in this test:

3,4-DCPA 50 Sodium dodecyl benzene sulfonate 5 Sodium citrate dihydrate3 Disodium phosphate 2 Attapulgite 40 After nine days the 4 week oldplants are examined for hebicidal eflects and the results recorded. Thedata on the 2 week old plants is taken 13 days after spraying.

The value of 3,4-DCPA as a pre-emergence herbicide is determined byplanting in greenhouse flats, seeds of eleven dilferent plants, eachrepresenting a principal botanical type. The flats are treated with3,4-DCPA at different rates by varying .the concentration of the3,4-DCPA in the composition applied to the soil.

The tests are terminated fourteen days after application and the resultsare observed and recorded.

The value of 3,4-DCPA with respect to its herbicidal effect on thevarious plants is indicated by a number as follows:

0-N0 phytotoxicity 1-Slight phytotoxicity 2Moderate phytotoxicity34evere phytotoxicity The following table of observed data demonstratesthe selective phytotoxicity of 3,4-DCPA:

TABLE IV Rate,lbslacre ABCDEFGHIJKLMNOPQR 10 13313330303001 4. 4.01000201300000 3. 0030300 3 00300000 The contact rating code for thefield tests is as follows: 6Complete kill 5Extreme injury 4-Severeinjury 3Moderate injury 2Slight injury 1-Very slight injury 0-No injuryTABLE III.-POST EMERGENCE FIELD TEST DATA 2week plants 4week plantsGeneral herbicidal elfects are obtained when 3, 4'di- Code deslgnation 8lbs/acre 2 lbs/acre 81bs./acre 2 lbs/acre chloroppnamilide retested at25 pounds per acre' What is claimed 1s: Crops 6 6 6 3 1.3',4-dichloropropionanilide.

6 6 6 2 g g g 2 References Cited 5 g g 2 FOREIGN PATENTS g g 2 g1,005,784 9/1957 Germany.

OTHER REFERENCES 2 i Beilsteins, Handbuch der Organischen Chemie, 4thed. 5 1 0 vol. 12, pp. 622 and 626. Berlin, Springer, 1929. 6 2 KingChemicals Evaluated As Insecticides And Repellents At Orlando, Fla. US.Department of Agriculture 6f 3 Handbook No. 69, pg. 285, Wash., D.C.,US. Government 3 5 Printing Office, 1954. 6 t f NATALIE TROUSOF, PrimaryExaminer. 4 4

